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Gross anatomy

Osteology

Compared to a typical rib, the first rib is short and thick and it has a single articular facet for the costovertebral joint. The first rib has a head, neck and shaft but lacks a discrete angle. The shaft is indented laterally, the groove for the subclavian artery, which contains the lowest brachial plexus trunk as well as the subclavian artery. Anterior to the scalene tubercle is another groove for the subclavian vein. There is no costal groove on its inferior surface. It has two tubercles:

transverse tubercle:posterior and lateral to the neck; bears an articular facet for the transverse process of T1